Oral irrigator



FIG. 1 is a front perspective view of a oral irrigator, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines in the drawings illustrate the portions of the oral irrigator, which form no part of the claimed design. 

CLAIM The ornamental design for an oral irrigator, as shown and described. 